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COSCUP 2016 - ROS + Gazebo機器人模擬器工作坊
This document provides an overview of ROS and Gazebo for robot simulation. It introduces ROS as a framework for robot software development that encourages code reuse. Key ROS concepts covered include nodes, topics, services, and packages. The document demonstrates creating simple ROS packages and nodes that publish, subscribe and use custom messages. Gazebo is introduced as a 3D physics simulator for robot control and environment simulation. Example demonstrations are provided on using Gazebo and ROS for SLAM with the PR2 robot in Rviz. Resources for further learning about ROS and Gazebo are also listed.
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COSCUP 2016 - ROS + Gazebo機器人模擬器工作坊
- 1. ROS + Gazebo機器人模擬器 工作坊 Presenter: 賴柏任 https://www.facebook.com/PoJenLai 08.20.2016 Brought to you by COSCUP 2016
- 2. Who am I •大學時有幸透過專題接觸 ROS，並陸續發表一 些 ROS 的介紹文章 https://pojenlai.wordpress.com/ • 研究所的論文內容也是用 ROS 來開發 https://github.com/Po- Jen/transparent_objects/tree/addedfeature • 工作閒暇之餘希望可以持續學習、也提供更多 資源給大家 http://blog.techbridge.cc/ http://weekly.techbridge.cc/ 2
- 3. Who am I •順便推薦一下 ROS.Taipei 社群 https://www.facebook.com/groups/122728288090359/ 3
- 4. Outline • ROS Introduction •ROS Basic Mechanism • ROS Tool Overview • Gazebo Introduction • Gazebo Usage • Navigation & SLAM 4
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- 6. What is ROS? 6 http://answers.ros.org/question/12230/what-is-ros-exactly-middleware-framework-operating-system/#18055 • ROS is acronym for Robot OS, but it is not a traditional OS like Windows, Ubuntu or Mac OS
- 7. What is ROS? 7 • Before we move on, we should clarify something • Robot software = Distributed computing system Decision Maker Object Recognition Object GraspingNavigation
- 8. What is ROS? 8 • ROS is a set of tools which enables – Easy construction of distributed computing systems (Programs can be individually designed and easily connected at runtime) – Code reuse – Configuring, starting, introspecting, debugging, visualizing, logging, testing, and stopping distributed computing systems
- 9. Why is ROSpreferred ? 9 • It encourages users not to reinvent the wheel
- 10. Why is ROSpreferred ? 10 • Many open-sourced libraries – SLAM (OpenSLAM) – Real-time control(OROCOS) – Path Planning (Openrave) – Vision (OpenCV, PCL) – 3D Simulator (Gazebo) – 3D Visualizer (Rviz)
- 11. Why is ROSpreferred ? 11 • Package can be written in multiple programming languages – C++ – Python – Lisp • And many more experimental support – C#, Go, Haskell, Java, Node.js, Lua, R, Ruby – http://wiki.ros.org/Client%20Libraries
- 12. Can ROS beused on different robot? 12 • Of course! • Check all robots using ROS - http://wiki.ros.org/Robots https://vimeo.com/146183080
- 13. ROS Basic Mechanism& Tool 13
- 14. 建立ROS workspace • 建立一個空的環境並編譯 –$ mkdir -p ~/catkin_ws/src – $ cd ~/catkin_ws/src – $ catkin_init_workspace – $ cd ~/catkin_ws – $ catkin_make 14
- 15. File System • Basicunit - package – CMakeLists.txt – package.xml • ROS package 使用catkin 這工具來進行編譯 – 按照 ROS 規定的格式寫code，就可以用catkin編譯 15
- 16. rosbuild v.s. catkin •rosbuild – ROS Groovy之前的編譯系統 – 有部分package仍未porting到catkin上，故仍需略懂 – 所有原始碼和編譯後的檔案都在同一資料夾下 • Catkin – ROS Groovy之後的編譯系統 – 原始碼和編譯後的檔案分離 • 接著直接來寫個node看看怎麼編譯 16
- 17. ROS Node • Basicunit of program 17 Decision Maker Object Recognition Object GraspingNavigation Node 1 Node 2 Node 3 Node 4
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- 19. Create our firstpackage & write a node • 步驟先全部列在這，接著讓我們一步步來做 – cd ~/catkin_ws/src catkin_create_pkg coscup_1_node rospy cd coscup_1_node vim src/node.py chmod +x src/node.py cd ../.. catkin_make source devel/setup.bash roscore rosrun coscup_1_node node.py rqt_graph 19
- 20. ROS Master • Howdo node knows each other? => ROS Master • Control the graph of nodes 20
- 21. rqt_graph • Visualization ofnodes and topics • Part of rqt (integrates lots of debugging tools) 21
- 22. How do ROSnode communicate? • ROS master as a message hub? – What if there are many nodes? 22
- 23. How do ROSnode communicate? • Let nodes communicates with each other directly – Topic, Service, ActionLib • If ROS does not exists – Socket – Shared memory – We have to take care of these tedious work. 23
- 24. ROS Topic • Publisher/Subscribermechanism (topic == bucket) 24 Perception Object Recognition Semantic Map Camera data Recognition result
- 25. rostopic • 寫一個publisher (一直丟字串到topic_name這個topic) –catkin_create_pkg coscup_2_topic rospy std_msgs cd coscup_2_topic vim src/publisher.py chmod +x src/publisher.py cd ../.. catkin_make source devel/setup.bash roscore rosrun coscup_2_topic publisher.py rqt_graph rostopic echo topic_name rostopic list rostopic list | grep topic 25
- 26. rqt_graph • Now, itshould looks like 26
- 27. rostopic • 寫一個subscriber (從topic_name這個topic取出data) –cd ~/catkin_ws/src cd coscup_2_topic vim src/subscriber.py chmod +x src/subscriber.py rosrun coscup_2_node subscriber.py rqt 27
- 28. rqt_graph • Now, itshould looks like 28
- 29. rqt • We cantry console 29
- 30. Define our ownmsg for topic • 創建一個只有一個int的msg – cd ~/catkin_ws/src cd coscup_2_topic mkdir msg vim msg/Num.msg vim package.xml vim CMakeLists.txt cd ../.. catkin_make source devel/setup.bash rosmsg show coscup_2_topic/Num 30
- 31. package.xml • Add builddependency and run dependency 31
- 32. CMakeLists.txt (1) • Addpackage dependency • Or you can – catkin_create_pkg coscup_2_topic rospy std_msgs message_generation 32
- 33. CMakeLists.txt (2) • Addbuild dependency • Add msg file • We use std_msgs/int64 in our msg file 33
- 34. Publish自己寫的msg • 步驟 – cd~/catkin_ws/src/coscup_2_topic/ vim src/my_msg_publisher.py chmod +x src/my_msg_publisher.py rosrun coscup_2_topic my_msg_publisher.py rostopic echo my_msg_topic_name 34
- 35. One more example •geometry_msgs/Twist 35
- 36. One more example •geometry_msgs/Vector3 36
- 37. How is theabstraction implemented? 37 /cmd_vel topic Base Controller Motor Speed geometry_msgs/Twist 將速度和角速度 轉成馬達命令
- 38. ROS Service • Query/ResponseStyle 38 Object Recognition Brain 1 query 2 response
- 39. ROS Service • 建立一個自己的srv格式 –cd ~/catkin_ws/src catkin_create_pkg coscup_3_service rospy std_msgs cd coscup_3_service mkdir srv vim srv/AddTwoInts.srv vim package.xml vim CMakeLists.txt cd ../.. catkin_make source devel/setup.bash rossrv show coscup_3_service/AddTwoInts 39
- 40. package.xml • Add builddependency and run dependency 40
- 41. CMakeLists.txt • Add servicefile • Add std_msgs dependency 41
- 42. ROS Service • 寫一個server –cd coscup_3_service vim src/add_two_ints_server.py cd ../.. source devel/setup.bash chmod +x src/add_two_ints_server.py rosrun coscup_3_service add_two_ints_server.py 42
- 43. ROS Service • 寫一個client，送出request給server –cd coscup_3_service vim src/add_two_ints_client.py chmod +x src/add_two_ints_client.py run coscup_3_service add_two_ints_client.py 5 6 43
- 44. Rviz • An importanttool for data visualization • 先啟動你們的Rviz – $ sudo apt-get install ros-indigo-rviz-* – $ roscore – $ rviz • Will be revisited when we use Gazebo 44
- 45. Find out moreon ROS Cheat Sheet • https://github.com/ros/cheatsheet 45
- 46.
- 47. What is Gazebo? • 3D物理模擬器 –機器人控制 –環境模擬 –物體物理特性模擬 • 用途廣泛 –DARPA Challenge也是用Gazebo來開發 47
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- 50. Started Gazebo • 先確保該安裝的東西都有被安裝 –$ sudo apt-get install ros-indigo-gazebo-* – $ sudo apt-get install ros-indigo-pr2-* • 啟動Gazebo – $ gazebo • 加入一些模型並存成world file 50
- 51. Play around withRviz 51
- 52.
- 53. 先來個 SLAM 的DEMO • Gazebo 開啟 PR2 進行 SLAM 53
- 54. 讓我們來實際操作 • Gazebo 開啟PR2 進行 SLAM – $ roslaunch pr2_gazebo pr2_empty_world.launch – $ 加入自己喜歡的模型 – $ roslaunch pr2_build_map.launch – $ rviz – $ roslaunch pr2_teleop teleop_keyboard.launch – $ rosrun map_server map_saver 54
- 55. SLAM 演算法簡介 • gmappingpackage (grid mapping) http://wiki.ros.org/gmapping • Grid map –Map is presented by 2D array –Each grid • 0: free • 1: occupied 55
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- 57. Map representation • Givensensor data zt and the poses of the sensor xt, estimate the map • 推導就不細講了 – http://ais.informatik.uni- freiburg.de/teaching/ws12/mapping/pdf/slam11-gridmaps-4.pdf 57
- 58. Resources you canleverage • ROS wiki http://wiki.ros.org/ • ROS Answers http://answers.ros.org/questions/ • Gazebo Answers http://answers.gazebosim.org/questions/ • ROS Taipei 中文資源整理 https://hackpad.com/-ROS-Blog--lnDeWhHXH4T 58
- 59. ROS 2.0 • 欲改進的點 –多機器人協作 (ROS 1.0是for PR2開發的) – 嵌入式平台開發 (不必再透過一層額外driver) – real-time系統 (能有更精準的控制能力) – 適用於產品開發 (原本偏向學術研究用) – 設計模式的建立 59
- 60. ROS 2.0 學習資源 •Official website – http://design.ros2.org/ • ROS 2.0 中文翻譯( under construction…) – http://po-jen.github.io/design/ • Tutorials from Erle-Robotics – http://erlerobotics.com/docs/Robot_Operating_System/ROS_2/T utorials/index.html 60
- 61. Thanks for joining,you guys rock! 61
- 62.
- 63. Example - ros_caffe •Github page – https://github.com/tzutalin/ros_caffe • Tutorial – http://www.artificialhumancompanions.com/integrating-ros-caffe- opencv-on-the-autonomous-deep-learning-robot/ • 使用topic_tools轉換Gazebo的PR2的topic name – rosrun topic_tools relay /wide_stereo/left/image_raw /camera/rgb/image_raw 63